摘要
通过对恒温和变温聚合所得不同聚合物收率(x)下的溶液丁苯共聚物(S-SBR)的^(13)CNMR谱田的解析,研究了S-SBR的序列分布、无规性、不均匀性和嵌段性与x和聚合温度的关系。用IR光谱研究了样品的微观组成。结果表明,50℃聚合,x<80％(质量)时,S-SBR中苯乙烯含量变化和序列分布比较均匀;x>80％时,无规性下降,不均匀性和嵌段性增加。在变温下聚合时,S-SBR中苯乙烯含量和序列分布随x的改变有不同程度的变化,S-SBR有明显的不均匀性。
The effect of polymerization temperature and conversion on the sequential distribution of styrene units, randomness, heterogeneity and blockness in solution styrene-butadiene copolymer synthesized with n-BuLi/THF initiator was investigated by 13C-NMR, and the micro-composition of the copolymer was examined by IR. When the polymerization temperature was maintained constantly at 50℃ and the conversion was below 80%, the contents of styrene and diad unit in the copolymer were rather homogeneously distributed. On the contrary, when the conversion was higher than 80%, the randomness and sequential homogeneity of the copolymer would get lower and blockness higher statistically. When the polymerization was carried out at changing temperatures, the sequential heterogeneity of the copolymer would increase at different degrees with changing conversions.
出处
《合成橡胶工业》
CAS
CSCD
北大核心
1990年第2期104-109,共6页
China Synthetic Rubber Industry
关键词
溶液法
丁二烯
苯乙烯
共聚物
序列
solution polymerized styrene-butadiene copolymers
sequence
polymer structure
polymerization temperature
conversion
nuclear magnetic resonance spectroscopy
